In general, composites (including metal matrix composites (MMCs)) are known. Composites typically include a matrix reinforced with particulates, whiskers, or fibers (e.g., short or long short fibers). Examples of metal matrix composites include aluminum matrix composite wires (e.g., silicon carbide, carbon, boron, or polycrystalline alpha alumina fibers embedded in an aluminum matrix), titanium matrix composite tapes (e.g., silicon carbide fibers embedded in a titanium matrix), and copper matrix composite tapes (e.g., silicon carbide or boron fibers embedded in a copper matrix). Examples of polymer matrix composites include carbon or graphite fibers in an epoxy resin matrix, glass or aramid fibers in a polyester resin, and carbon and glass fibers in an epoxy resin.
One use of composite wire (e.g., metal matrix composite wire) is as a reinforcing member in bare overhead electrical power transmission cables. One typical need for cables is driven by the need to increase the power transfer capacity of existing transmission infrastructure.
Desirable performance requirements for cables for overhead power transmission applications include corrosion resistance, environmental endurance (e.g., UV and moisture), resistance to loss of strength at elevated temperatures, creep resistance, as well as relatively high elastic modulus, low density, low coefficient of thermal expansion, high electrical conductivity, and high strength. Although overhead power transmission cables including aluminum matrix composite wires are known, for some applications there is a continuing desire, for example, for more desirable sag properties.